
<!DOCTYPE html>
<html lang="en">
    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <title>Document</title>
        <style>
            *{
                margin:0px;
                padding:0px;
                list-style: none;
            }
            div{
                width: 520px;
                height: 280px;
                margin:100px auto;
                position: relative;
               
                overflow: hidden;
            }
            ul{
                width:9999px ;
                transform: translateX(0px);
            }
            ul li{
                float: left;
            }
            ol{
                position: absolute;
                bottom:10px;
                left: 50%;
                
                transform: translateX(-50%);
            }
            ol li{
                width: 10px;
                height: 10px;
                border-radius: 50%;
                background:white;
                float: left;
                margin:0px 4px;
                cursor: pointer;
            }
            span{
                position: absolute;
                top:50%;
                transform: translateY(-50%);
                background:lime;
                cursor: pointer;
            }
            span:nth-of-type(1){
                left:10px;
            }
            span:nth-of-type(2){
                right:10px;
            }
            .current{
                background: #f60;
            }
        </style>
    </head>
    <body>
        <div id="wrap">
          
            <ul id="box">
                <li>
                    <img src="images/pic1.jpg" alt="">
                </li>
                <li>
                    <img src="images/pic2.jpg" alt="">
                </li>
                <li>
                    <img src="images/pic3.jpg" alt="">
                </li>
                <li>
                    <img src="images/pic4.png" alt="">
                </li>
            </ul>
            
            <ol id="list">
                <li class="current"></li>
                <li></li>
                <li></li>
                <li></li>
            </ol>
         
            <span id="left"><</span>
            <span id="right">></span>
            <script>
               
                var box=document.getElementById('box');
                var wrap=document.getElementById('wrap');
                var left=document.getElementById('left');
                var right=document.getElementById('right');
               
                var list=document.getElementById('list').children;
                
                var num=0;
                var timer;
               
                function fn(){
              
                    timer=setInterval(function(){
                        num++;
                        if(num>3){
                            num=0;
                        }
 
                        box.style.transform='translate('+(-520*num)+'px)';
                  
                        for(var i=0;i<list.length;i++){
                            list[i].className='';
                        }
                     
                        list[num].className='current'
 
                    },1000)
                }
                fn()
 
             
                wrap.onmouseenter=function(){
                 
                    clearInterval(timer)
                }
            
                wrap.onmouseleave=function(){
                    fn()
                }
 
            
                for(var n=0;n<list.length;n++){
                 
                    list[n].zsh=n;
                    list[n].onclick=function(){
                    
                        for(var i=0;i<list.length;i++){
                            list[i].className='';
 
                        }
                        this.className='current'
                    
                        num=this.zsh
                        box.style.transform='translate('+(-520*num)+'px)';
                    }
                }
              
                right.onclick=function(){
                        num++;
                        if(num>3){
                            num=0;
                        }
                    
                        box.style.transform='translate('+(-520*num)+'px)';
              
                        for(var i=0;i<list.length;i++){
                            list[i].className='';
                        }
                     
                        list[num].className='current'                  
                }
            
                left.onclick=function(){
                        num--;
                        if(num<0){
                            num=3;
                        }
                       
                        box.style.transform='translate('+(-520*num)+'px)';
            
                        for(var i=0;i<list.length;i++){
                            list[i].className='';
                        }
               
                        list[num].className='current'
                    
                }
            </script>
        </div>
    </body>
</html>
